Friday, February 1, 2013

New study finds wind farms last only 50% of claimed lifetime

A peer-reviewed study finds from actual performance data of wind farms in the UK and Denmark that the life of wind turbines is only about 50% of that claimed by the wind industry. The report finds the performance "of wind farms declines substantially as they get older, probably due to wear and tear" and that "This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years. After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike."

The work has been conducted by one of the UK’s leading energy & environmental economists, Professor Gordon Hughes of the University of Edinburgh, and has been anonymously peer-reviewed. This groundbreaking study applies rigorous statistical analysis to years of actual wind farm performance data from wind farms in both the UK and in Denmark.

The results show that after allowing for variations in wind speed and site characteristics the average load factor [performance] of wind farms declines substantially as they get older, probably due to wear and tear. By 10 years of age the contribution of an average UK wind farm to meeting electricity demand has declined by a third.

This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years. After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike.

Policymakers expecting wind farms built before 2010 to be contributing towards CO2 targets in 2020 or later must allow for the likelihood that the total investment required to meet these targets will be much larger than previous forecasts have suggested. As a consequence, the lifetime cost per unit (MWh) of electricity generated by wind power will be considerably higher than official estimates.